一、拓扑图：
 
用分发列表过滤掉路由更新，以达到路由筛选的目的_第1张图片
二、配置各路由器的IP和协议，然后在R2上做重分发。保证两边都能学到各自的路由，为了学到的全部都是明细路由，以体现实验效果。我们把R2和R3的RIP V2都关闭自动汇总，
1、下面看一下R1的route:
 
R1#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
 
Gateway of last resort is not set
 
     172.168.0.0/24 is subnetted, 4 subnets
C       172.168.0.0 is directly connected, Loopback0
C       172.168.1.0 is directly connected, Loopback0
C       172.168.2.0 is directly connected, Loopback0
C       172.168.3.0 is directly connected, Loopback0
     172.16.0.0/24 is subnetted, 1 subnets
C       172.16.255.0 is directly connected, Serial1/1
O E2 192.168.255.0/24 [110/200] via 172.16.255.2, 00:00:03, Serial1/1
O E2 192.168.0.0/24 [110/200] via 172.16.255.2, 00:00:03, Serial1/1
O E2 192.168.1.0/24 [110/200] via 172.16.255.2, 00:00:03, Serial1/1
O E2 192.168.2.0/24 [110/200] via 172.16.255.2, 00:00:03, Serial1/1
O E2 192.168.3.0/24 [110/200] via 172.16.255.2, 00:00:03, Serial1/1
 
2、再来看一下R3的路由表：
 
R3#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
 
Gateway of last resort is not set
 
     172.168.0.0/16 is variably subnetted, 4 subnets, 2 masks
R       172.168.1.0/24 [120/10] via 192.168.255.2, 00:00:02, Serial1/0
R       172.168.0.1/32 [120/10] via 192.168.255.2, 00:00:02, Serial1/0
R       172.168.2.0/24 [120/10] via 192.168.255.2, 00:00:02, Serial1/0
R       172.168.3.0/24 [120/10] via 192.168.255.2, 00:00:02, Serial1/0
     172.16.0.0/24 is subnetted, 1 subnets
R       172.16.255.0 [120/10] via 192.168.255.2, 00:00:02, Serial1/0
C    192.168.255.0/24 is directly connected, Serial1/0
C    192.168.0.0/24 is directly connected, Loopback0
C    192.168.1.0/24 is directly connected, Loopback0
C    192.168.2.0/24 is directly connected, Loopback0
C    192.168.3.0/24 is directly connected, Loopback0
 
3、现在两边明细路由都有了，那么现在我要用distribute的命令过滤特定路由条目。不过在这之前我们要建立访问控制列表。
 
4、在 R2上 distribute针对 ospf区域的 RIP发进来的路由，以过滤掉 192.168.2.0/24和 192.168.3.0/24的网络：
R2(config)#access-list 1 deny 192.168.2.0 0.0.0.255
R2(config)#access-list 1 deny 192.168.3.0 0.0.0.255
R2(config)#access-list 1 permit any  (这一条一定要加上，不然的话会全部过滤掉RIP来的路由)
R2(config-router)# router ospf 1
R2(config-router)#distribute-list 1 out rip (对外部RIP路由进行distribute,引用访问控制列表1)
5、再来看一下 R1的路由表：
R1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
 
Gateway of last resort is not set
 
     172.168.0.0/24 is subnetted, 4 subnets
C       172.168.0.0 is directly connected, Loopback0
C       172.168.1.0 is directly connected, Loopback0
C       172.168.2.0 is directly connected, Loopback0
C       172.168.3.0 is directly connected, Loopback0
     172.16.0.0/24 is subnetted, 1 subnets
C       172.16.255.0 is directly connected, Serial1/1
O E2 192.168.255.0/24 [110/200] via 172.16.255.2, 00:01:31, Serial1/1
O E2 192.168.0.0/24 [110/200] via 172.16.255.2, 00:01:31, Serial1/1
O E2 192.168.1.0/24 [110/200] via 172.16.255.2, 00:01:31, Serial1/1 (现在只能学到这三条路由了,过滤掉了192.168.2.0和192.168.3.0这两个网络)
6、我们再在 R2上 distribute针对 RIP区域的 OSPF发进来的路由，以过滤掉 172.168.0.0/24和 172.168.1.0/24的网络：
R2(config)#access-list 2 deny 172.168.0.0 0.0.0.255 (建立一个列表2对源地址的过滤)
R2(config)#access-list 2 deny 172.168.1.0 0.0.0.255 (建立一个列表2对源地址的过滤)
R2(config)#access-list 2 permit any  (切记不要忘了加这一条，不然所有路由都学不到)
R2(config-router)# router rip
R2(config-router)#distribute-list 2 out ospf 1(对外部ospf路由进行distribute,引用访问控制列表2)
7、下面我再来看一下 R3的路由表：
R3#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route
 
Gateway of last resort is not set
 
     172.168.0.0/24 is subnetted, 2 subnets
R       172.168.2.0 [120/10] via 192.168.255.2, 00:00:01, Serial1/0 
R       172.168.3.0 [120/10] via 192.168.255.2, 00:00:01, Serial1/0  (只有这两条路由了)
     172.16.0.0/24 is subnetted, 1 subnets
R       172.16.255.0 [120/10] via 192.168.255.2, 00:00:01, Serial1/0
C    192.168.255.0/24 is directly connected, Serial1/0
C    192.168.0.0/24 is directly connected, Loopback0
C    192.168.1.0/24 is directly connected, Loopback0
C    192.168.2.0/24 is directly connected, Loopback0
C    192.168.3.0/24 is directly connected, Loopback0
R3#
 
通过上面的图示可以看到 172.168.0.0/24和 172.168.1.0/24的网络已经被过滤掉了。